John Robie (Cary Grant) is a notorious but retired jewel thief or “cat burglar,” nicknamed “The Cat,” who now tends to his vineyards in the French Riviera. A series of robberies that closely resemble his in style leads the police to believe that the Cat is up to his old tricks again. They come to arrest him, and he adeptly gives them the slip.

He immediately seeks refuge with his old gang from his days in the French Resistance, a group of ex-cons whose patriotic work led to grants of parole that depend on them keeping their noses clean. Bertani, Foussard, and the others are all under a cloud while the Cat is at large, and they blame Robie. Still, when the police arrive at Bertaniâ€™s restaurant, Foussardâ€™s daughter Danielle (Brigitte Auber) spirits her old flame to safety.

Robie enlists the aid of an insurance man of Bertani’s acquaintance, H. H. Hughson (John Williams), in order to prove his innocence. Robie’s plan is to catch the new cat burglar in the act. To do this, he obtains a list of the most expensive jewels on the Riviera from the reluctant Hughson. The first names on the list are Jessie Stevens (Jessie Royce Landis) and her daughter Francie (Grace Kelly). Robie strikes up acquaintance with them â€” something met with delight by Jessie, a pretense of modesty with Francie, and claws-baring jealousy from Danielle.

…

Robie speeds back to his vineyard and Francie races after to convince him that he does need her in his life. He agrees, but seems less than thrilled about including her mother.